• Journal of the Optical Society of Korea
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• v.12 no.3
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• pp.170-173
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• 2008

In this study, we simulated a statistical model of FCS(fluorescence correlation spectroscopy) based on a Poisson process to understand and explain observations of the experiment performed on molecules of ultra-low concentration by the home-built laser-scanning confocal microscope. The statistical model confirmed that the relative mean square amplitude of fluctuations is shown to be inversely proportional to the average number of molecules, even in the ultra-low concentration, if some conditions are satisfied. Signal-to-noise ratio and the variability of dwelling time under the confocal volume were found to be effective conditions for the experiment.

• Journal of the Korean Society of Visualization
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• v.8 no.1
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• pp.46-52
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• 2010

In the present study, we employed the confocal laser scanning microscopy (CLSM) system to visualize the blood flow field with $1{\times}1{\mu}m^2$ spatial resolution. Based on the confocal microscopic image of red blood cells (RBCs), we performed the velocity vector field measurement and evaluated characteristics of cell migration from the cell depleted layer thickness calculation. The rat and mouse's blood were supplied into a micro glass tubes in vitro. The line scanning rate of confocal microscopy was 15 kHz for a $500{\times}500$ pixels image. As a result, the red blood cell itself can be used as a tracer directly without any kind of invasive tracer particle to get the velocity vector field of blood flow by performing particle image velocimetry (PIV) technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.249-250
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• 2007

• The Zoological Society Korea : Newsletter
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• v.16 no.1
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• pp.60-65
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• 1999

• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.11a
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• pp.123-127
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• 2006

Hybrid type microscope with a Scanning Confocal Microscope (SCM) and a shear-force Atomic Force Microscope (AFM) is suggested and preliminarily studied. A image of $120{\times}120{\mu}m^2$ is obtained within 1 second by SCM because scan speed of a X-axis and Y-axis are 1kHz and 1Hz, respectively. Shear-force AFM is able to correctly measure the hight and width of sample with a resolution 8nm. However, the scan speed is slow and it is difficult to distinguish a surface composed of different kinds of materials. We have carried out the measurement of total image of a sample by SCM and an exact analysis of each image by shear-force AFM.

• Restorative Dentistry and Endodontics
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• v.26 no.1
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• pp.1-8
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• 2001

Dental Caries which has high prevalence rate, accounts for majority of dental diseases. Many treatment and preventive treatment has been developed, thereby reducing the prevalence rate, but in our country, fluoridization has not spread widely yet, so prevention has not been done satisfactorily. When dental caries progresses, irreversible damage of tooth structure occurs. In initial dental caries, demineralizing tooth structure can be remineralized, so restorative treatment is unnecessary. In this study, 20 teeth restored with composite resin without fluoride release were used and divided into two groups. Incipient dental caries were artificially made and demineralization procedure was done for 1 and 2 weeks, for each group. Changes in mineral contents around the margins were analysed with confocal laser scanning microscope. The results were as follow. 1. Both total fluorescence of the lesion and average fluorescence of the lesion of remineralized samples decreased compared to demineralizing state. (p＜0.01) 2. Confocal laser scanning microscopy can be used in quantitative analysis of mineral change. In result, confocal laser scanning microscopy can be used in quantitative analysis of mineral change and it could be used in many different fields of dentistry in the future.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.1-12
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• 2006

The purpose of this study were to evaluate the efficacy of the newly developed Digital Imaging Fiber-Optic Trans-illumination (DIFOTI) system in detecting carious lesions in vivo as gold standard with confocal laser scanning microscopy and compared the efficacy of traditional radiography and DIFOTI system in vito as gold standard with confocal laser scanning microscopy, too. For the in vivo study, the subject pool consisted of 23 grammar school age patients just prior to entering the mixed dentition phase Each patient was given a DIFOTI examination of the anterior and posterior teeth. During $6{\sim}8$ months, the naturally expire primary teeth were collected and the efficacy of DIFOTI system was compared with confocal laser scanning microscopy. For in vitro study, 40 primary teeth were collected and decalcified by Carbopol decalcification solution for 1, 2, 4 and 8 days. Every experiment period, all teeth were DIFOTI examined and sectioned to take an image of confocal laser scanning microscopy Sensitivity and specificity were calculated from the result of DIFOTI examine and confocal laser scanning microscopy analysis. The results are as follows : 1. From the in vivo study, the sensitivity of DIFOTI examine was 0. 61 and specificity was 0.63. 2. From the in vivo study, the sensitivity of DIFOTI examine was 0.71 and specificity was 0.75.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.979-983
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• 2013

The three-dimensional measurement method of confocal systems is a spot scanning method which has a high resolution and good illumination efficiency. However, conventional confocal systems had a weak point in that it has to perform XY axis scanning to achieve FOV (Field of View) vision through spot scanning. There are some methods to improve this problem involving the use of a galvano mirror [1], pin-hole array, etc. Therefore, in this paper we propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array in a dual microscope configuration. We made an area scan possible by using a combination MLA (Micro Lens Array) and pin-hole array, and used an objective lens to improve the light transmittance and signal-to-noise ratio. Additionally, we made it possible to change the objective lens so that it is possible to select a lens considering the reflection characteristic of the measuring object and proper magnification. We did an experiment using 5X, 2.3X objective lens, and did a calibration of height using a VLSI calibration target.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.301-302
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• 2009

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.394-401
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• 2013

A new Rockwell hardness (HRC) model using a volumetric parameter by a least square and fractal interpolation method is suggested. The results are also investigated in comparison to real measured hardness data. For this purpose, the measurement of an indented volume is performed using a confocal laser scanning microscope (CLSM), and the captured height encoded image (HEI) is used as an original surface for the calculation of the indented volume. After configuring the surface, the constructed volume is calculated and used as an independent variable for HRC hardness modeling. The hardness model is established using an experimental modeling technique involving a least square algorithm and fractal interpolating model, and this suggested model can be used to reliably predict the Rockwell hardness. These techniques can also be applied to the modeling of the Brinnell and Vickers hardnesses using a volumetric variable.